There has been known a technique in related art that a surface of a cooling chamber inside which a cooling medium circulates is pressed onto a portion to be cooled of a heat generating body by a liquid chamber to which a pressurizing fluid is introduced.
Japanese Examined Patent Application Publication No. 59-015400, Japanese Laid-open Patent Publication No. 2011-171569, and Japanese Laid-open Patent Publication No. 2007-173578 are examples of related art.